Radon in Well Water Testing

Q: What symptoms can I get from drinking water with fecal coliforms?

Fecal coliforms, like *E. coli*, can make people sick with symptoms that include diarrhea, cramps, nausea, and headaches [Understanding Positive Coliform Tests](https://www.home-water-purifiers-and-filters.com/coliform-bacteria-well-water.php?srsltid=AfmBOopQX84E_YwRHagwKBJNEpQUJjYrkyeg6HapmrV_rNFg21HtIsb6). In severe cases, particularly with specific types of *E. coli*, it can even lead to kidney failure. If infants, young children, the elderly, or people with compromised immune systems live in

Last updated: April 2026

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Quick Answer

Test your well water at least once every year for total coliform bacteria, nitrates, total dissolved solids, and pH level CDC Guidelines for Well Water Testing.
Private wells are not regulated by the U.S. Environmental Protection Agency (EPA); owners are responsible for testing their own water CDC Guidelines for Well Water Testing.
A positive test for total coliforms means it is likely that harmful germs—including certain viruses, bacteria, and parasites—are also in your water CDC Guidelines for Well Water Testing.
If fecal coliforms or E. coli are found, your water has definitely come into contact with human or animal waste What to Do About Coliform Bacteria in Well Water.

As a private well owner, you carry the important responsibility of ensuring your drinking water is safe. Unlike public water systems, private wells are not subject to the U.S. Environmental Protection Agency's (EPA) regulations, meaning government officials do not regulate, treat, or monitor your tap water CDC Guidelines for Well Water Testing. This puts the onus on you to conduct regular testing. We recommend testing your well water at least once every year for key indicators like total coliform bacteria, nitrates, total dissolved solids, and pH levels. A positive result for total coliforms suggests the potential presence of harmful germs, while finding fecal coliforms or E. coli confirms contact with human or animal waste, signaling a serious contamination risk that needs immediate attention.

Why is Well Water Testing Important?

Well water testing is critical because it directly impacts the health and safety of your household. As a private well owner, you are solely responsible for checking your water quality. The U.S. Environmental Protection Agency (EPA) sets rules for public drinking water systems, but these rules do not apply to privately owned wells CDC Guidelines for Well Water Testing. This means no government agency regulates, treats, or monitors the tap water coming from your private well. Without regular testing, you could be unknowingly consuming water contaminated with bacteria, chemicals, or other harmful substances that can lead to serious health issues.

Understanding this responsibility is the first step toward safeguarding your water supply. Even though local governments do not actively monitor private wells, they can often provide assistance and guidance on how to get your well water tested. They can also help you understand the specific concerns in your local area, which might influence what additional contaminants you should test for beyond the annual recommendations. Ignoring well water testing can lead to significant health risks, especially for vulnerable populations such as infants, young children, the elderly, or individuals with compromised immune systems. These groups are more susceptible to illnesses caused by waterborne pathogens.

The Owner's Responsibility

The entire burden of ensuring water safety rests on the well owner. This responsibility extends beyond just initial testing. It includes understanding the potential sources of contamination, interpreting test results, and taking appropriate action if contamination is found. For example, if your test results show harmful germs or chemicals, you should consider drinking bottled water or another safe source of water immediately CDC Guidelines for Well Water Testing. This proactive approach is essential for preventing waterborne diseases.

Lack of Public Oversight

The absence of EPA regulation for private wells highlights the unique position of well owners. Public water systems undergo rigorous testing and treatment processes to meet federal standards. Private wells, however, operate independently of these systems. This independence means well owners must adopt a similar vigilance, acting as their own water utility managers. While this can seem daunting, resources are available to help. Local health or environmental departments are key partners in this process, offering guidance and support. They can help you navigate the testing process, understand complex results, and recommend solutions to make your well water safe.

Protecting Your Family's Health

Regular testing is the best defense against unknown contaminants. Many harmful substances in well water are odorless, colorless, and tasteless, making them impossible to detect without laboratory analysis. Coliform bacteria, for instance, are often not harmful themselves but serve as "indicator organisms." Their presence indicates that a pathway exists for disease-causing microorganisms to enter your water Understanding Positive Coliform Tests. Without testing, you would never know if your well has such a pathway, potentially exposing your family to serious health risks. Therefore, routine testing is not just a recommendation; it is a fundamental aspect of maintaining a healthy home environment.

What Should You Test Your Well Water For Annually?

Every year, you should test your well water for total coliform bacteria, nitrates, total dissolved solids, and pH level CDC Guidelines for Well Water Testing. These are fundamental indicators of water quality that can alert you to potential problems. Beyond these basic tests, it is smart to reach out to your local health department. They can provide specific advice on other germs or chemicals that might be a concern in your particular area, based on local geology, agricultural practices, or industrial activities. Always use a state-certified laboratory for your water testing to ensure accurate and reliable results.

These annual tests are a foundational step in well water management. Total coliforms are often harmless themselves, but their presence can signal that harmful germs are likely in your water CDC Guidelines for Well Water Testing. Nitrates, on the other hand, can be a direct health hazard, especially for infants. Total dissolved solids (TDS) measure all the inorganic and organic substances in the water, which can affect taste and indicate the presence of other contaminants. The pH level tells you how acidic or alkaline your water is, which can impact pipe corrosion and the effectiveness of water treatment systems.

Key Annual Water Quality Indicators

Testing for certain indicators annually provides a snapshot of your well's health.

Total Coliforms: These bacteria are found in soil, decaying plants, and the intestines of warm-blooded animals. While many are harmless, their presence indicates a potential pathway for disease-causing organisms to enter your well Understanding Positive Coliform Tests. If the total coliform count is high, it suggests that harmful germs, including certain viruses, bacteria, and parasites, are also likely present in your water CDC Guidelines for Well Water Testing.
Nitrates: Often linked to agricultural runoff or septic system failures, high nitrate levels are particularly dangerous for infants, potentially causing "blue baby syndrome" (methemoglobinemia).
Total Dissolved Solids (TDS): This measures the concentration of dissolved substances in your water. High TDS can indicate hard water, which can cause mineral buildup in pipes and appliances, or it could signal other contaminants. Culligan offers various water softening solutions for well owners dealing with hard water issues Well Water Softeners | Well Water Softening | Culligan.
pH Level: The pH of your water affects its corrosivity and how effectively disinfectants work. Water that is too acidic or too alkaline can cause pipes to leach metals or reduce the lifespan of your plumbing system.

Localized Concerns and Additional Testing

Your geographical location and surrounding environment play a significant role in determining additional contaminants you should test for. For example, if you live near agricultural areas, pesticides or herbicides might be a concern. Near industrial sites, heavy metals or volatile organic compounds (VOCs) could be present. Homes with older plumbing might need to test for lead. Your local health department is the best resource for identifying these specific regional risks. They can help you understand the geology, soil types, and potential sources of contamination unique to your area, guiding you toward a more comprehensive testing regimen.

The Importance of State-Certified Laboratories

Choosing a state-certified laboratory for your water testing is not just a recommendation; it is crucial for accuracy and reliability. These laboratories adhere to strict protocols and quality control measures, ensuring that their test results are precise and legally defensible. A certified lab will provide clear instructions on how to collect your water sample properly, which is vital for preventing contamination during the collection process itself. Contamination during sampling can lead to false positives, causing unnecessary worry and expense. After you receive your results, your health department can help you understand what they mean and what steps to take next CDC Guidelines for Well Water Testing. This partnership between well owners, certified labs, and local health departments forms the backbone of effective well water management.

What Do Coliform Bacteria Indicate?

Coliform bacteria are a broad group of many different types of bacteria that serve as "indicator organisms" in water quality testing. They are found naturally in various environments, including soil, decaying vegetation, and the intestines of warm-blooded animals, including humans Understanding Positive Coliform Tests. While many coliforms are harmless themselves, their presence in well water indicates that a pathway exists for disease-causing microorganisms—such as harmful bacteria, viruses, and protozoan cysts—to enter the water supply. This is why a positive test for coliforms should always be taken seriously.

The significance of coliforms lies in their role as easily detectable proxies for more dangerous pathogens. Coliform bacteria typically get into your water the same way as germs that do cause disease, for example, from a sewage leak, but they are much easier to test for CDC Guidelines for Well Water Testing. This makes them an invaluable tool for initial screening. When we detect total coliforms, it suggests a breach in the well system or surrounding environment that could allow fecal matter, and thus harmful pathogens, to contaminate the drinking water.

Total Coliforms vs. Fecal Coliforms and E. coli

It is important to understand the distinctions within the coliform group:

Total Coliforms: This is a broad category. A high total coliform count indicates that harmful germs, including certain viruses, bacteria, and parasites, are likely also in your water CDC Guidelines for Well Water Testing. These bacteria live in the digestive systems of people and animals, in soil, on plants, and in surface water like lakes or rivers. Most total coliforms generally will not make you sick, but they signal a potential problem.
Fecal Coliforms: This is a specific kind of total coliform bacteria. People's and animals' poop contain millions of these bacteria CDC Guidelines for Well Water Testing. A positive test for fecal coliforms means that feces, and the harmful germs in feces, have likely gotten into your well water CDC Guidelines for Well Water Testing.
E. coli: Escherichia coli (E. coli) is a specific bacterium within the fecal coliform group, and you can test for it by itself CDC Guidelines for Well Water Testing. A positive test for E. coli is a strong indicator of recent fecal contamination. Joel Pigg, John W. Smith, and Diane E. Boellstorff from the Texas Water Resources Institute state, "If E. coli or other fecal coliform bacteria are in well water, the water has come into contact with human or animal waste and could cause illness" What to Do About Coliform Bacteria in Well Water. While most E. coli strains are harmless, some specific types can cause serious illness CDC Guidelines for Well Water Testing. A standard water quality indicator test for E. coli will not identify these dangerous types; a more specific test is needed if you suspect a dangerous strain.

Health Risks Associated with Fecal Contamination

When fecal coliforms or E. coli are present, it signifies that your water has been compromised by human or animal waste. This opens the door to a host of pathogens that can cause severe gastrointestinal and other illnesses. Pathogens that can be indicated by coliforms include Cryptosporidium, Norovirus, Campylobacter, and Salmonella, as well as specific dangerous strains of E. coli like E. coli (OH:157) Understanding Positive Coliform Tests. Symptoms of illness from these pathogens can include diarrhea, cramps, nausea, and headaches, and in severe cases, can even lead to kidney failure Understanding Positive Coliform Tests. For infants, young children, the elderly, and individuals with weakened immune systems, these illnesses can be particularly severe and even life-threatening. Therefore, a positive test for fecal contamination demands immediate action to protect public health.

What Does a Positive Coliform Test Mean?

A positive total coliform test indicates the potential presence of harmful germs in your well water, but it doesn't always mean E. coli is present. Coliforms are common bacteria found in soil, decaying plants, and animal guts, so their presence alone suggests a pathway for contamination Understanding Positive Coliform Tests. However, if your test specifically detects fecal coliforms or E. coli, then it definitely means your water has come into contact with human or animal waste, posing a direct health risk What to Do About Coliform Bacteria in Well Water. While many E. coli strains are harmless, some specific types can cause serious illness, although a general water quality test won't differentiate these dangerous types CDC Guidelines for Well Water Testing.

When a lab reports a positive total coliform result, it means that bacteria from this group were detected in your water sample. This finding is a red flag. It tells us that your well system may have a vulnerability, such as a cracked well casing, a faulty well cap, or contamination from surface runoff, that allows bacteria to enter. Because coliforms are easier to test for than many disease-causing organisms, they serve as crucial indicators. A high total coliform count strongly suggests that harmful germs, including viruses, bacteria, and parasites, are also likely present in your water CDC Guidelines for Well Water Testing.

Interpreting Total Coliform Results

A positive result for total coliforms means your water is potentially unsafe to drink. These bacteria are widespread in nature, including in soil and on plants, and they can easily enter a well if its integrity is compromised. While the total coliforms themselves may not make you sick, their presence indicates a breach in your well's protection. This breach allows not only coliforms but also potentially more dangerous pathogens to enter your drinking water. For instance, if a sewage leak or animal waste enters the groundwater, it can introduce both harmless coliforms and disease-causing bacteria, viruses, or parasites. Therefore, a positive total coliform test necessitates further investigation.

The Grave Concern of Fecal Coliforms and E. coli

The detection of fecal coliforms or E. coli elevates the concern significantly. These bacteria are specifically associated with the feces of warm-blooded animals and humans. "If E. coli or other fecal coliform bacteria are in well water, the water has come into contact with human or animal waste and could cause illness," as stated by Joel Pigg, John W. Smith, and Diane E. Boellstorff from the Texas Water Resources Institute What to Do About Coliform Bacteria in Well Water. This is a definitive sign of fecal contamination, meaning there's an immediate risk of waterborne illness.

While most strains of E. coli are harmless and live naturally in the gut, some specific types can cause severe sickness, including diarrhea, cramps, nausea, and headaches, and in rare cases, kidney failure Understanding Positive Coliform Tests. The standard water quality test for E. coli is designed to detect its presence as an indicator of fecal contamination, not to identify the specific dangerous strains that cause serious illness CDC Guidelines for Well Water Testing. If you suspect your water is contaminated with a dangerous type of E. coli, you would need to use a more specific type of test to find it. However, any positive E. coli test should be treated as a serious health threat, especially for vulnerable individuals like infants, young children, the elderly, or those with compromised immune systems.

Addressing Contamination Pathways

A positive coliform test, especially for fecal coliforms or E. coli, indicates that a pathway exists for contaminants to enter your well. This pathway could be due to several issues, such as:

Wellhead integrity issues: A damaged or improperly sealed well cap can allow surface water, insects, or small animals to enter.
Cracked or leaky well casing: This can allow shallow groundwater or surface runoff to seep into the well.
Contaminated groundwater: Nearby septic systems, agricultural runoff, or overflowing floodwaters can introduce bacteria into the aquifer that supplies your well.
Poor well construction: If the well was not properly sealed during construction, it can be vulnerable to contamination.
Sampling error: Sometimes, contamination can occur during the collection process itself. This is why retesting is often recommended.

Understanding what a positive test means is the first step toward troubleshooting and resolving the contamination. It highlights the need for immediate action to protect your drinking water supply and the health of those who consume it.

What Should You Do After a Positive Coliform Test?

If your well water tests positive for coliform bacteria, the first step is to avoid panic, but take the results seriously, especially if vulnerable people live in your household Understanding Positive Coliform Tests. The next crucial action is to retest your water, specifically for fecal coliform bacteria or E. coli, to confirm the contamination What to Do About Coliform Bacteria in Well Water. It's vital to follow the laboratory's instructions carefully when collecting this new sample; remove any aerator, filter, or hose from the faucet, wash your hands, and do not touch the inside of the container. If contamination is confirmed, you should immediately consider drinking bottled water or another safe source of water until the issue is resolved CDC Guidelines for Well Water Testing.

A positive total coliform test is an indicator, not always a definitive confirmation of dangerous fecal contamination. As certified water technicians from Home-Water-Purifiers-and-Filters.com advise, "First of all, don’t panic! Yes, a positive total coliform test can mean your water is contaminated with e-coli, but not always" Understanding Positive Coliform Tests. This is why retesting is so important. The initial sample might have been contaminated during collection, or the detected coliforms might be non-fecal types that are less concerning. However, the presence of any coliforms indicates that something may be wrong with the well, highlighting the need for vigilance.

Retesting for Confirmation

When retesting, focus specifically on fecal coliforms or E. coli. This targeted test will confirm whether the contamination is from human or animal waste, which is the primary concern for health. Coliform bacteria are very common and do not necessarily indicate that the water has come into contact with human or animal waste. But the presence of fecal coliform or E. coli in water definitely indicates contamination by contact with human or animal waste What to Do About Coliform Bacteria in Well Water.

To ensure an accurate retest, strict adherence to sampling procedures is essential:

Follow Lab Instructions: Each state-certified laboratory will provide detailed instructions for collecting a water sample. These instructions are designed to prevent external contamination during the collection process.
Prepare the Faucet: Before collecting water, remove any aerator, filter, or hose from the faucet you plan to use. These attachments can harbor bacteria and lead to a false positive result.
Cleanliness is Key: Wash your hands thoroughly before handling the sample bottle. Crucially, do not touch the inside of the container or the inside of its cap to avoid introducing bacteria from your skin.
Run the Water: Let the cold water run for several minutes (typically 2-5 minutes) before collecting the sample. This clears out any standing water in the pipes and ensures you are sampling directly from the well supply.

Immediate Actions for Confirmed Contamination

If the retest confirms the presence of fecal coliforms or E. coli, immediate action is necessary to protect health.

Secure Safe Drinking Water: Stop drinking your well water. Switch to bottled water or use another verified safe water source for all consumption, including drinking, cooking, making ice, and brushing teeth.
Contact Local Authorities: Reach out to your local health department or environmental department immediately. They are equipped to help you understand the test results, identify potential sources of contamination, and recommend the best course of action to make your well water safe to drink CDC Guidelines for Well Water Testing. They may also recommend that you test your well water more often in the future.
Identify and Fix the Source: Work with professionals to identify and repair the source of contamination. This could involve inspecting your well casing, cap, and seals, checking nearby septic systems, or addressing issues with surface water runoff.
Disinfect Your Well: Often, shock chlorination is recommended to disinfect the well and kill bacteria. This process involves adding a strong chlorine solution to the well and plumbing system, allowing it to sit, and then flushing it out. This should ideally be done by a qualified well professional.
Retest After Treatment: After addressing the contamination source and disinfecting the well, you must retest the water to confirm that the bacteria have been eliminated. Multiple clear tests may be required before the water is deemed safe for consumption again.

Taking these steps promptly and thoroughly is essential for restoring the safety of your well water and protecting the health of your household.

How Can Your Health Department Help?

Your local health or environmental department serves as a vital resource for private well owners, especially after receiving water test results. They can help you understand what your test results mean, translating complex scientific data into clear, actionable information CDC Guidelines for Well Water Testing. Beyond interpretation, these departments can advise on the necessary next steps to make your well water safe to drink, offering guidance tailored to your specific situation and local environmental conditions. They may also recommend that you test your well water more often if certain risks or persistent issues are identified.

Local health departments are staffed with experts who understand local geology, potential sources of contamination, and effective remediation strategies. Since private wells are not regulated by the U.S. Environmental Protection Agency (EPA), these local agencies fill a critical gap by providing support and expertise to individual well owners who are responsible for their own water safety CDC Guidelines for Well Water Testing. Their assistance can range from explaining the implications of total coliform presence to outlining steps for shock chlorination after fecal contamination is confirmed.

Understanding Test Results

One of the primary ways your health department helps is by demystifying your water test results. Lab reports can contain technical terms and numerical values that are not always intuitive. A health department professional can explain:

What was detected: Clearly identify if total coliforms, fecal coliforms, or E. coli were found, and what each means for your health. For example, they can clarify that while many coliforms are harmless, their presence indicates a pathway for disease-causing microorganisms Understanding Positive Coliform Tests.
Health implications: Discuss the potential health risks associated with the detected contaminants, especially for vulnerable household members like infants or the elderly.
Possible sources of contamination: Based on your well's location and surrounding environment, they can help you brainstorm likely sources of the contamination, such as a failing septic system, agricultural runoff, or a compromised wellhead.

This interpretive service is invaluable, as it empowers well owners to make informed decisions about their water quality and health.

Guidance on Remediation and Treatment

Once the problem is understood, the health department can offer practical advice on how to resolve it. This guidance might include:

Temporary solutions: Recommending immediate steps like boiling water or drinking bottled water if fecal contamination is confirmed CDC Guidelines for Well Water Testing.
Well inspection and repair: Advising on inspecting your well structure for cracks, faulty seals, or other entry points for contaminants.
Well disinfection: Providing instructions or referrals for shock chlorination, a common method for killing bacteria in the well and plumbing system.
Long-term treatment options: Suggesting permanent water treatment solutions, such as UV disinfection systems or continuous chlorination, depending on the nature and persistence of the contamination. For issues like hard water that might be related to overall water quality, a Culligan water softener could be a relevant solution if other contaminants are addressed Shop Water Softeners | Water Softener Systems | Culligan.

These recommendations are often based on best practices and local regulations, ensuring that the solutions are effective and appropriate for your situation.

Recommendations for Ongoing Monitoring

Beyond immediate remediation, your local health department can help you establish a long-term monitoring plan. If your well has experienced contamination, they may advise you to test your water more frequently than the annual recommendation CDC Guidelines for Well Water Testing. This increased vigilance helps ensure that the problem has been fully resolved and that no new contamination issues arise. They can also inform you about other specific germs or chemicals to test for based on where you live, such as arsenic, lead, or pesticides, which might not be part of the standard annual panel but are relevant to your area CDC Guidelines for Well Water Testing. Leveraging the expertise of your local health department is a critical step in maintaining a safe and healthy private well water supply for years to come.

Frequently Asked Questions

How often should I test my well water?

You should test your well water at least once every year for total coliform bacteria, nitrates, total dissolved solids, and pH level CDC Guidelines for Well Water Testing. Your local health department may recommend more frequent testing or additional tests based on your specific location and any past contamination issues. Regular testing helps ensure your water remains safe to drink.

Does the EPA regulate private well water?

No, the U.S. Environmental Protection Agency's (EPA) rules that protect public drinking water systems do not apply to privately owned wells CDC Guidelines for Well Water Testing. As a private well owner, you are responsible for testing your well to make sure the water is safe to drink. Local governments do not regulate, treat, or monitor tap water from private wells, but they can help you get your well water tested.

What is the difference between total coliforms and fecal coliforms?

Total coliforms are a broad group of bacteria found in soil, plants, and animal digestive systems. While many are harmless, a high count indicates that harmful germs are likely present CDC Guidelines for Well Water Testing. Fecal coliforms are a specific type of total coliform found in the poop of people and animals. Their presence, or the presence of E. coli, definitely means the water has come into contact with human or animal waste What to Do About Coliform Bacteria in Well Water.

What symptoms can I get from drinking water with fecal coliforms?

Fecal coliforms, like E. coli, can make people sick with symptoms that include diarrhea, cramps, nausea, and headaches Understanding Positive Coliform Tests. In severe cases, particularly with specific types of E. coli, it can even lead to kidney failure. If infants, young children, the elderly, or people with compromised immune systems live in the household, a positive test should be taken very seriously.

Who should I contact if my well water tests positive for bacteria?

If your well water tests positive for harmful germs or chemicals, you should contact your local health or environmental department CDC Guidelines for Well Water Testing. They can help you understand the test results, advise on next steps to make your well water safe to drink, and may recommend more frequent testing. Consider drinking bottled water or another safe source of water until the issue is resolved.